Dictionary

A dictionary is a reference work that lists the words of a language, usually in alphabetical order, and provides information about their meanings, pronunciations, and usage. Most entries include the headword, pronunciation (often shown with IPA), part of speech, one or more senses with definitions, notes on usage, and example sentences. Many dictionaries also present etymologies, inflected forms, pronunciation variants, synonyms and antonyms, cross-references, and abbreviations or symbols indicating frequency or register.

There are several types of dictionaries. Monolingual dictionaries explain words in the language they describe; bilingual or multilingual dictionaries translate between languages; learner’s dictionaries tailor definitions and usage notes for language learners; specialized dictionaries focus on domains such as law, medicine, or technology; and general dictionaries aim for broad coverage. Online and mobile dictionaries are common today, frequently updated and often using corpus data to illustrate current usage.

History and development: early lexicographic efforts included glossaries and lists in various languages. Milestones include the Chinese Shuowen Jiezi, Sanskrit glossaries, and the medieval English Table Alphabeticall (1604). Samuel Johnson’s Dictionary (1755) helped standardize spelling and usage. In the 19th and 20th centuries, lexicography grew with descriptive approaches and larger reference works; the digital era enabled rapid updates, searchable databases, and crowd-sourced or editorially curated content.

Lexicography is the study and practice of compiling dictionaries. Dictionaries differ from thesauri, which organize words by related meanings rather than by single-word definitions. Limitations include language change, regional biases, and the need for continual revision to reflect current use.